Biomaterial and cellular implants:foreign surfaces where immunity and coagulation meet

Blood ◽  
2021 ◽  
Author(s):  
Jayachandran N Kizhakkedathu ◽  
Edward M Conway
Keyword(s):  
Inflammatory Response ◽  
Regenerative Processes ◽  
Innate Response ◽  
Functional Integrity ◽  
Cellular Events ◽  
Foreign Substance ◽  
Evolutionarily Conserved ◽  
Foreign Surface ◽  
Context Specific

Exposure of blood to a foreign surface in the form of a diagnostic or therapeutic biomaterial device or implanted cells or tissues, elicits an immediate, evolutionarily conserved thrombo-inflammatory response by the host. Primarily designed to protect against invading organisms following an injury, this innate response features instantaneous activation of several blood-borne, highly interactive and well-orchestrated cascades and cellular events that limit bleeding, destroy and eliminate the foreign substance/cells, and promote healing and a return to homeostasis via delicately balanced regenerative processes. In the setting of blood-contacting synthetic or natural biomaterials and implantation of foreign cells/tissues, innate responses are robust, albeit highly context-specific. Unfortunately, they tend to be less than adequately regulated by the host's natural anti-coagulant/anti-inflammatory pathways, thereby jeopardizing the functional integrity of the device, as well as the health of the host. Strategies to achieve biocompatibility with a sustained return to homeostasis, particularly while the device remains in situ and functional, continue to elude scientists and clinicians. In this review, some of the complex mechanisms by which biomaterials and cellular transplants provide a "hub" for activation and amplification of coagulation and immunity - thrombo-inflammation - will be discussed, with a view toward the development of innovative means of overcoming the innate challenges.

In situ forming chitosan hydrogels: Preliminary evaluation of the in vivo inflammatory response

2017 ◽  
Vol 75 ◽  
pp. 279-285 ◽  
Author(s):  
Maria José Moura ◽  
João Brochado ◽  
Maria Helena Gil ◽  
Maria Margarida Figueiredo
Keyword(s):  
Inflammatory Response ◽  
Preliminary Evaluation ◽  
In Situ Forming ◽  
Chitosan Hydrogels

Nanotechnology Enabled In Situ Orthopaedic Sensors for Personalized Medicine

2012 ◽  
Vol 86 ◽  
pp. 40-50
Author(s):  
Sirinrath Sirivisoot ◽  
Thomas J. Webster
Keyword(s):  
Bone Growth ◽  
Electrochemical Sensors ◽  
Electrochemical Analysis ◽  
Matrix Proteins ◽  
Implant Design ◽  
Implant Surface ◽  
Cellular Events ◽  
Bone Deposition ◽  
Made In

Although improvements have been made in implant design to increase bone formation and promote successful osseointegration using nanotechnology, the clinical diagnosis of early bone growth surrounding implants remains problematic. The development of a device allowing doctors to monitor the healing cascade and to diagnose potential infection or inflammation is necessary. Biological detection can be examined by the electrochemical analysis of electron transfer (or redox) reactions of extracellular matrix proteins involved in bone deposition and resorption. The use of nanomaterials as signal amplifiers in electrochemical sensors has greatly improved the sensitivity of detection. Nanotechnology-enabled electrochemical sensors that can be placed on the implant surface itself show promise as self-diagnosing devices in situ, possibly to detect new bone growth surrounding the implant and other cellular events to ensure implant success.

ATP depletion in slow-twitch red muscle of rat

1987 ◽  
Vol 253 (3) ◽  
pp. C426-C432 ◽  
Author(s):  
D. M. Whitlock ◽  
R. L. Terjung
Keyword(s):  
Adenine Nucleotide ◽  
Atp Depletion ◽  
Cellular Events ◽  
Contraction Condition ◽  
Red Muscle ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Fast Twitch

Rat slow-twitch muscle, in contrast to fast-twitch muscle, maintains its ATP content near normal during intense stimulation conditions that produce rapid fatigue. An extensive depletion of adenine nucleotide content by the deamination of AMP to IMP + NH3, typical of fast-twitch muscle, does not occur. We evaluated whether this response of slow-twitch muscle could be simply due to failure of synaptic transmission or related to cellular conditions influencing enzyme activity. Stimulation of soleus muscles in situ via the nerve or directly in the presence of curare at 120 tetani/min for 3 min resulted in extensive fatigue but normal ATP contents. Thus the lack of ATP depletion must be related to cellular events distal to neuromuscular transmission. Even nerve and direct muscle stimulation (with curare) during ischemia did not cause a large depletion of ATP or a large elevation of lactate content (12.0 +/- 0.7 mumol/g), even though the decline in tension was essentially complete. However, if the same tension decline during ischemia was prolonged by stimulating for 10 min at 12 tetani/min a large decrease in ATP (2.24 +/- 0.09 mumol/g) and increase in IMP (2.47 +/- 0.16 mumol/g) and lactate (30.4 +/- 2.0 mumol/g) content occurred. Thus adenine nucleotide deamination to IMP can occur in slow-twitch muscle during specific contraction conditions. The cellular events leading to the activation of AMP deaminase require an intense contraction condition and may be related to acidosis caused by a high lactate content.

scholarly journals A review of the endemic Hawaiian Drosophilidae and their host plants

Zootaxa ◽  
2008 ◽  
Vol 1728 (1) ◽  
pp. 1 ◽  
Author(s):  
KARL N. MAGNACCA ◽  
DAVID FOOTE ◽  
PATRICK M. O’GRADY
Keyword(s):  
Host Plant ◽  
Host Plants ◽  
Ecological Specialization ◽  
Primary Host ◽  
Evolutionarily Conserved ◽  
Rare And Endangered ◽  
Species Groups ◽  
Plant Families ◽  
Insight Into

The Hawaiian Drosophilidae is one of the best examples of rapid speciation in nature. Nearly 1,000 species of endemic drosophilids have evolved in situ in Hawaii since a single colonist arrived over 25 million years ago. A number of mechanisms, including ecological adaptation, sexual selection, and geographic isolation, have been proposed to explain the evolution of this hyperdiverse group of species. Here, we examine the known ecological associations of 326 species of endemic Hawaiian Drosophilidae in light of the phylogenetic relationships of these species. Our analysis suggests that the long-accepted belief of strict ecological specialization in this group does not hold for all taxa. While many species have a primary host plant family, females will also oviposit on non-preferred host plant taxa. Host shifting is fairly common in some groups, especially the grimshawi and modified mouthparts species groups of Drosophila, and the Scaptomyza subgenus Elmomyza. Associations with types of substrates (bark, leaves, flowers) are more evolutionarily conserved than associations with host plant families. These data not only give us insight into the role ecology has played in the evolution of this large group, but can help in making decisions about the management of rare and endangered host plants and the insects that rely upon them for survival.

Distribution of TGG repeat-related sequences in 'Trovita' orange (Citrus sinensis Osbeck) chromosomes

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1251-1254
Author(s):  
Tomoki Matsuyama ◽  
Tomoya Akihama ◽  
Yuji Ito ◽  
Mitsuo Omura ◽  
Kiichi Fukui
Keyword(s):  
In Situ Hybridization ◽  
Citrus Sinensis ◽  
Fluorescent In Situ Hybridization ◽  
Repeated Sequences ◽  
Evolutionarily Conserved ◽  
M13 Phage ◽  
Citrus Genome

The clone pAS"C" is a sequence related to M13 phage minisatellite sequences isolated from bovine DNA. It contains TGG repeats, and related sequences are abundant in the Citrus genome. Fluorescent in situ hybridization (FISH) signals detected using this clone as a probe showed that the TGG repeat-related sequences are found on all the Citrus chromosomes, but are not found in Citrus-specific CMA+/DAPI- heterochromatic regions located at the extreme ends of each chromosome. These data suggest that the TGG-repeated sequences are evolutionarily conserved and that the CMA+/DAPI- heterochromatic regions were added to the chromosome ends at a recent stage in Citrus evolution.Key words: Citrus, minisatellite, microsatellite, SSRs, FISH.

scholarly journals Wound Healing and Omega-6 Fatty Acids: From Inflammation to Repair

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Jéssica R. Silva ◽  
Beatriz Burger ◽  
Carolina M. C. Kühl ◽  
Thamiris Candreva ◽  
Mariah B. P. dos Anjos ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Wound Healing ◽  
Current Knowledge ◽  
Phagocytic Capacity ◽  
Cellular Events ◽  
Species Survival ◽  
Evolutionarily Conserved ◽  
Omega 6 ◽  
Cell Migration And Proliferation

Wound healing is an evolutionarily conserved process that is essential for species survival. Wound healing involves a series of biochemical and cellular events that are tightly controlled, divided into 3 concomitant and overlapping phases: inflammation, proliferation, and remodelling. Poor wound healing or a chronic wound represents a silent epidemic that affects billions of people worldwide. Considering the involvement of immune cells in its resolution, recent studies are focused on investigating the roles of immune nutrients such as amino acids, minerals, and fatty acids on wound healing. Among the fatty acids, much attention has been given to omega-6 (ω-6) fatty acids since they can modulate cell migration and proliferation, phagocytic capacity, and production of inflammatory mediators. The present review summarizes current knowledge about the role of ω-6 fatty acids in the wound healing context.

Transcriptional mapping and genomic analysis of the cardiac atria and ventricles

2002 ◽  
Vol 12 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Xiao-Song Zhao ◽  
Teresa D. Gallardo ◽  
Ling Lin ◽  
Jeoffrey J. Schageman ◽  
Ralph V. Shohet
Keyword(s):  
Genomic Analysis ◽  
Myocyte Enhancer Factor 2 ◽  
Noncoding Sequences ◽  
Transcriptional Mapping ◽  
Evolutionarily Conserved ◽  
Conserved Noncoding Sequences ◽  
Detailed Evaluation ◽  
Development Structure ◽  
Enhancer Factor

The atria and ventricles of the heart have distinct development, structure, and physiology. However, only a few of the genes that underlie the differences between these tissues are known. We used a murine cardiac cDNA microarray to identify genes differentially expressed in the atria and ventricles. The reliability of these findings is supported by highly concordant repetition of hybridization, recognition of previously known atrial and ventricular isoforms of contractile proteins, and confirmation of results by quantitative PCR and in situ hybridization. We examined the most differentially regulated genes for evolutionarily conserved noncoding sequences and found that atrial-expressed genes have more predicted myocyte enhancer factor-2 (MEF2) binding sites than ventricle-predominant genes. We confirmed that messages for MEF2 family members are more abundant in the atria, as are their protein products. Moreover, the activity of a transgenic reporter construct for MEF2 activity is preferentially upregulated in the atria in response to hypertrophic stimuli. This study provides a greater understanding of the molecular differences between atria and ventricles and establishes the framework for an anatomically detailed evaluation of cardiac transcriptional regulation.

New insights into PKC family affairs: three novel phosphorylation sites in PKCϵ and at least one is regulated by PKCα

2008 ◽  
Vol 411 (2) ◽  
pp. e15-e16 ◽  
Author(s):  
Christer Larsson
Keyword(s):  
Phosphorylation Sites ◽  
Functional Importance ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Cellular Processes ◽  
Biochemical Journal ◽  
Pkc Isoforms ◽  
Evolutionarily Conserved ◽  
The Individual

PKCϵ (protein kinase Cϵ) is a serine/threonine kinase, and a member of the PKC family of isoforms. The different PKC isoforms regulate many cellular processes of importance for disease. It is therefore desirable to obtain tools to specifically modulate the activity of the individual isoforms and to develop markers of PKC activity. The paper by Durgan et al. in this issue of the Biochemical Journal has taken us some steps further towards these goals. In the paper they identify three previously unknown phosphorylation sites in PKCϵ. All of them are specific for the ϵ isoform, evolutionarily conserved and tightly regulated. The phosphorylation of one site is critical for the binding of PKCϵ to 14-3-3β, suggesting it is of functional importance. The results provide important novel findings that uncover new aspects of PKCϵ regulation and reveal new possibilities for detecting PKCϵ activity in situ.

scholarly journals Autonomous dry stone

2020 ◽  
Vol 4 (3-4) ◽  
pp. 127-140 ◽  
Author(s):  
Ryan Luke Johns ◽  
Martin Wermelinger ◽  
Ruben Mascaro ◽  
Dominic Jud ◽  
Fabio Gramazio ◽  
...  
Keyword(s):  
Error Propagation ◽  
Planning Process ◽  
Embodied Energy ◽  
Average Weight ◽  
Terrain Mapping ◽  
Planning Algorithm ◽  
Context Specific ◽  
Robotic Construction ◽  
Stone Walls

AbstractOn-site robotic construction not only has the potential to enable architectural assemblies that exceed the size and complexity practical with laboratory-based prefabrication methods, but also offers the opportunity to leverage context-specific, locally sourced materials that are inexpensive, abundant, and low in embodied energy. We introduce a process for constructing dry stone walls in situ, facilitated by a customized autonomous hydraulic excavator. Cabin-mounted LiDAR sensors provide for terrain mapping, stone localization and digitization, and a planning algorithm determines the placement position of each stone. As the properties of the materials are unknown at the beginning of construction, and because error propagation can hinder the efficacy of pre-planned assemblies with non-uniform components, the structure is planned on-the-fly: the desired position of each stone is computed immediately before it is placed, and any settling or unexpected deviations are accounted for. We present the first result of this geometric- and motion-planning process: a 3-m-tall wall composed of 40 stones with an average weight of 760 kg.

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